144 0001239501 XXXXXXXX LIVE 0001447362 Castle Biosciences, Inc. 001-38984 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 1-866-788-9007 Derek Maetzold Officer Common Goldman Sachs & Co. LLC 200 West Street New York NY 10282 43019 834998.79 29008281 08/13/2025 NASD Common 08/08/2025 Acquired as compensation -- Performance Awards Issuer N 43019 08/08/2025 Compensation N The Maetzold Descendants 2020 Trust dtd 12/4/2020 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 06/27/2025 8068 163804.6 The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 06/27/2025 660 13399.98 The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 06/27/2025 660 13399.98 Derek Maetzold 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 06/27/2025 4944 100378.03 Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 06/27/2025 6924 140577.97 The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 06/27/2025 660 13399.98 The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 06/27/2025 660 13399.98 The sales of shares set forth herein are made in connection with a selling plan dated 11/11/2024 that is intended to comply with Rule 10b5-1(c). 08/13/2025 11/11/2024 Goldman Sachs & Co. LLC on behalf of Derek Maetzold